20-30 deg F is not cold- I'm calling BS. Some of these old semi-auto guns just like a particular brand of ammo which may or may not be available in this day and time. What did Grand Pa shoot? Suspect whatever was on the shelf but most likely standard velocity ammo. You may need to buy various brands and try them- they are available online- or maybe get a GS to make you a slightly stronger spring to accommodate for the HV ammo. Save the CCI for the manual extractor and/or modern guns. That said maybe some worn parts if shot 10's of thousands of rounds. I would love to know exactly how many rounds of .22 's I have shot. You may be on the right track with some parts exchange.
